Subtract 20/21 from 40/18
1st number: 2 4/18, 2nd number: 20/21
40/18 - 20/21 is 80/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
40/18 = 40 × 7/18 × 7 = 280/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
20/21 = 20 × 6/21 × 6 = 120/126 - Subtract the two like fractions:
280/126 - 120/126 = 280 - 120/126 = 160/126 - After reducing the fraction, the answer is 80/63
- In mixed form: 117/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/18-20/21 40/18-40/21 40/36-20/21 40/18-20/42 40/18-60/21 40/54-20/21 40/18-20/63 40/90-20/21